var conn = new ActiveXObject("ADODB.Connection");
conn.ConnectionString = "driver={sql
server};server=(local);database=YourDBName;uid=sa;pwd=;";
conn.Open();

var cmd = new ActiveXObject("ADODB.Command");
cmd.ActiveConnection = conn;
cmd.CommandText = "your_stored_proc_name";
cmd.CommandType = 0x0004;  // adCmdStoredProc

var param = new ActiveXObject("ADODB.Parameter");
param.Name = "@output_parameter";
param.Direction = 0x0002;  // adParamOutput
param.Type = 3; // adInteger
cmd.Parameters.Append(param);

var param2 = new ActiveXObject("ADODB.Parameter");
param2.Name = "@input_parameter";
param2.Direction = 0x0001; // adParamInput
param2.Type = 200; // adVarChar
param2.Size = 10;
param2.Value = "testing123";
cmd.Parameters.Append(param2);

var parameters;
var recs;
cmd.Execute(recs, parameters);

conn.Close();

cmd.Parameters.Refresh;

XDocument.UI.Alert(cmd.Parameters[0].Value);  // Retrieve output param value

----
For a sample ODBC connection string corresponding to your database type look
on
http://www.connectionstrings.com

Look on http://www.winscripter.com/ASP/Database/46.aspx to find the correct
ADO constants (such as adChar or adVarChar, etc.) in JScript for the data
types used in your stored procedure.

You might experience ADO security issues when running this code. Perhaps you
should look into using web services
(http://msdn.microsoft.com/library/en-us/odc_ip2003_ta/html/OfficeInfoPathWebServ
iceASPNET.asp?frame=true) if this does not work for you.
---
S.Y.M. Wong-A-Ton